Efficient polarizing agents for dynamic nuclear polarization (DNP) enhanced magic angle spinning (MAS) NMR spectroscopy are of high current interest due to the potential to significantly boost NMR sensitivity. While most efforts have centered on cross-effect (CE) or Overhauser effect (OE) mechanisms, yielding enhancement factors up to ∼300 at 9.4 T, radicals yielding solid effect (SE) DNP have seen less development. Here we model the comparative performance of OE and SE mechanisms and then measure